A typical driver airbag module is mounted on a vehicle steering wheel usually fixed to a hub, which in turn is coupled to a steering shaft. Consequently a driver airbag rotates in unison with the steering wheel. Since the deployment of the airbag may occur at different rotational orientations of the steering wheel with respect to the vehicle driver, the driver airbag has to be circular or symmetrical shaped to provide always the same shape of protection surface to the driver.
In some motor vehicles, for instance sport cars, the maximum diameter of the airbag is limited by the high inclination of the windscreen and the front door jambs. Recently, steering wheel assemblies have been provided that allow the driver airbag module to remain in a stationary position with respect to the vehicle during rotation of the steering wheel. This type of module is known as a non-rotating, or static, driver airbag module. Advantageously, non-rotating driver airbags may provide airbags having shapes other than circular, since there is no rotation of the airbag with respect to the driver. Non-rotating driver airbag modules allow for localized increases of the airbag volume. Thus driver airbags may be designed to fit the internal volume of a particular vehicle when deployed to better protect the driver regardless of the angular orientation of the steering wheel.